In an automotive head-up display (HUD), external environment information and display information are visually confirmed simultaneously by projecting display information such as navigation information, etc., onto the windshield.
In particular, a display can be provided to perceive an image at a depthward position matched to the background and increase a sense of depth and/or three-dimensionality by viewing the display with one eye. For example, JP-A 2009-244355 (Kokai) discusses the use in such a case of multiple images in which the sizes of shapes that are displayed are sequentially changed in a direction away from the position of the human.
On the other hand, the operation of the car is not performed instantaneously; and decisions are made by the driver until when the driver performs the driving operations. Easier use and safer operations can be realized by effectively making the decisions.
For example, an arrow or the like that provides a prompt to change the travel direction of the car is one image presented to the human in a HUD. In the case where this arrow or the like is presented to the human, i.e., the driver of the car, special display information is necessary for the human to effectively perform the decision operation.